"We are looking at how we might transport Americans to Cyprus. Once in Cyprus, Americans can then board commercial aircraft for onward travel," an embassy statement said.

The State Department said Friday that Americans in Lebanon should consider leaving when it is safe to do so, and officials made contingency plans for the evacuation of people who cannot leave on their own.

"Our best advice is for people to assess their security situation," State Department spokesman Sean McCormack said Friday. "Right now ... from the U.S. government perspective, there aren't any reliable ways to get out by air, land or sea."

The U.S. estimates 25,000 Americans live or work in Lebanon, but U.S. officials assume that far fewer would choose to leave if they could.

Saturday's embassy statement said the State Department was continuing to work "around the clock" with the Defense Department on a plan to help American citizens leave Lebanon safely.

A statement posted on the embassy's Web site on Friday urged Americans in Lebanon to be extremely vigilant and avoid non-essential travel because of the escalating violence in the conflict with Israel.

European nations lined up ferries, buses and airplanes to evacuate thousands of their citizens from Lebanon.

France, which has historic ties to Lebanon and 17,000 citizens residing there, announced plans Saturday to ferry French nationals to Cyprus where Air France flights would be waiting to bring them to Paris. The voluntary evacuations will begin Sunday. In addition to French residents, up to 6,000 other Europeans were estimated to be in Lebanon.

However, France was also clearly preparing for the worst, sending two tactical transport C 160 aircraft with three helicopters to Cyprus as well as a transport vessel with two hospital units and four more helicopters - to leave for the region on Sunday, the Defense Ministry said. The frigate Jean de Vienne was ordered deployed in the eastern Mediterranean. The ministry called the measures "precautionary."

"We want to take all the necessary measures for the security of our citizens," Prime Minister Dominique de Villepin said at the end of a crisis meeting on Saturday. The government would evaluate the situation in Lebanon "hour by hour," he said. He did not raise the possibility of mandatory evacuations.

WASHINGTON (CNN) -- The fighting that erupted in Lebanon has prompted the Pentagon to develop scenarios for evacuating American citizens, estimated to number around 25,000, military sources told CNN.

The rapid widening of the Mideast conflict this week has created great concern in the U.S. government, which doesn't want Americans in Lebanon caught in the middle of a shooting war.

Such moves would start small, if they happen at all, the sources said. There has been no immediate request for help and no order to move any military personnel.

The State Department has set up a Middle East Task Force to coordinate policy and share information. Defense Department officials are part of the team to talk about any possible plans for American evacuation -- a customary move, said State Department spokesman Sean McCormack.

While "contingency planning" is being done, no evacuations were under way, McCormack told reporters. Americans were being asked to stay in contact with the American Embassy.

Foreign governments are drawing up plans for a voluntary evacuation of their nationals from Lebanon as Israel kept up air strikes against its neighbour in retaliation for attacks by Hezbollah militants.

Britain is to send two Royal Navy warships to the Middle East as part of the contingency plans for a possible evacuation, the ministry of defence said in London on Saturday.

A ministry of defence spokeswoman said the aircraft carrier Illustrious and the warship Bulwark would shortly be sent to the Middle East, but she would not comment on news reports that they would be used to evacuate Britons from the area.

"As you would expect we are monitoring the situation closely and are engaging in prudent contingency planning," said the spokeswoman, speaking on condition of anonymity in line with government policy.

"As part of this HMS Illustrious and HMS Bulwark will shortly head toward the region. They have been given no specific tasking."

Britain also advised its citizens not to attempt to leave Lebanon under their own steam and said it had not yet made a decision on whether to evacuate its nationals. There are 10,00 Britons in Lebanon, plus a further 10,000 with joint nationality.

France, Italy and Sweden followed Britain's lead in preparing to evacuate their citizens, mainly by land to Syria or by ferry to the Mediterranean island of Cyprus.

WASHINGTON (CNN) -- Americans could be evacuated from Lebanon using an "air bridge" of fast-moving aircraft, U.S. military officials said Saturday.

Pentagon and U.S. State Department officials are working on contingency plans to get about 25,000 people out of Lebanon to escape Israel's military campaign, launched after two Israeli soldiers were kidnapped by Hezbollah guerrillas.

An "air bridge" is the term for planes that would move in swiftly and ferry people out in quick succession.

Planners are focusing on flying people from the Lebanese capital of Beirut to the island of Cyprus, officials said.

PARIS, France (AP) -- European nations lined up ferries, buses and airplanes to evacuate thousands of their citizens from Lebanon, increasingly under siege from Israeli attacks.

France, which has historic ties to Lebanon and 17,000 citizens residing there, announced plans Saturday to ferry French nationals to Cyprus where Air France flights would be waiting to bring them to Paris.

The voluntary evacuations will begin Sunday. In addition to French residents, up to 6,000 other French citizens were estimated to be in Lebanon visiting.

"We want to take all the necessary measures for the security of our citizens," Prime Minister Dominique de Villepin said at the end of a crisis meeting Saturday morning. The government would evaluate the situation in Lebanon "hour by hour" and adapt measures if needed, he said. He did not raise the possibility of mandatory evacuations.